Predictors of Mortality in Acute Myocardial Infarction Complicated by Cardiogenic Shock despite Intra-Aortic Balloon Pump: Opportunities for Advanced Mechanical Circulatory Support in Asia.

Introduction: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) mortality remains high despite revascularization and the use of the intra-aortic balloon pump (IABP). Advanced mechanical circulatory support (MCS) devices, such as catheter-based ventricular assist devices (cVAD), may impact mortality. We aim to identify predictors of mortality in AMI-CS implanted with IABP and the proportion eligible for advanced MCS in an Asian population. Methods: We retrospectively analyzed a cohort of Society for Cardiovascular Angiography and Intervention (SCAI) stage C and above AMI-CS patients with IABP implanted from 2017-2019. We excluded patients who had IABP implanted for indications other than AMI-CS. Primary outcome was 30-day mortality. Binary logistic regression was used to calculate adjusted odds ratios (aOR) for patient characteristics. Results: Over the 3-year period, 242 patients (mean age 64.1 ± 12.4 years, 88% males) with AMI-CS had IABP implanted. 30-day mortality was 55%. On univariate analysis, cardiac arrest (p < 0.001), inotrope/vasopressor use prior to IABP (p = 0.004) was more common in non-survivors. Non-survivors were less likely to be smokers (p = 0.001), had lower ejection fraction, higher creatinine/ lactate and lower pH (all p < 0.001). On multi-variate analysis, predictors of mortality were cardiac arrest prior to IABP (aOR 4.00, CI 2.28-7.03), inotrope/vasopressor prior to IABP (aOR 2.41, CI 1.18-4.96), lower arterial pH (aOR 0.02, CI 0.00-0.31), higher lactate (aOR 2.42, CI 1.00-1.19), and lower hemoglobin (aOR 0.83, CI 0.71-0.98). Using institutional MCS criteria, 106 patients (44%) would have qualified for advanced MCS. Conclusions: Early mortality in AMI-CS remains high despite IABP. Many patients would have qualified for higher degrees of MCS.

Microvolt T-wave alternans in early repolarization syndrome associated with ventricular arrhythmias: A case report.

Despite early repolarization (ER) syndrome being usually considered benign, its association with severe/malignant ventricular arrhythmias (VA) was also reported. Microvolt T-wave alternans (MTWA) is an electrocardiographic marker for the development of VA, but its role in ER syndrome remains unknown. A 90-second 6-lead electrocardiogram from an ER syndrome patient, acquired with the Kardia recorder, was analyzed by the enhanced adaptive matched filter for MTWA quantification. On average, MTWA was 50 µV, higher than what was previously observed on healthy subjects using the same method. In our ER syndrome patient, MTWA plays a potential role in VA development in ER syndrome.

Effects of sex on clinical outcomes of hypertrophic cardiomyopathy in Singapore.

Introduction: Despite the growing recognition that sex can affect the presentation and outcomes in hypertrophic cardiomyopathy (HCM), this relationship is understudied in Asians. Therefore, we aimed to explore sex differences in Asian patients with HCM. Method: A total of 295 consecutive patients diagnosed with HCM were recruited from a tertiary cardiology centre from 2010 to 2017 over a mean of 3.9±2.7 years. We evaluated the effects of sex on the outcomes of HCM in Asian patients. Results: HCM patients were more commonly men (72%). Women were older and had more comorbidities, including hypertension and atrial fibrillation. On transthoracic echocardiography, the indexed left ventricular end-systolic and end-diastolic volumes were similar, but more women had more-than-moderate mitral regurgitation and had a smaller left ventricular outflow tract (LVOT). Women more commonly had findings of obstructive physiology with significant LVOT obstruction, defined as >30 mmHg at rest. The use of implantable cardioverter defibrillators was similar across sexes. On multivariable analysis, women were found to be more likely to develop progressive heart failure requiring admission (hazard ratio [HR] 2.10, 95% confidence interval [CI] 1.05-4.71, P=0.021) but had a lower rate of all-cause mortality (HR 0.36, 95% CI 0.19-0.70, P=0.003). Conclusion: Women diagnosed with HCM were older, had more comorbidities and were more likely to develop heart failure while men had a higher risk of all-cause mortality.